Software level

Because this sampling is just the incrementation of a delay and changing the phase of a pulse, we have complete control at the software level of how we want to sample the real and imaginary data in t. ... 

Hardware, all Software levels, network (model, version, further details - Test location(s)... 

One final point is that this scenario is an example of risk existing in a system which is functioning under normal rather than fault conditions. No amount of faultfinding purely at the software level would have identified these hazards. 

Among all non-resonant activation techniques, BAD has been shown to have unique advantages for the formation of product ions. Due to the necessity to utilize an additional power supply for generating the DC component, such an approach has not been used in any commercial mass spectrometer. Conversely, in the DIT, variation of the duty cycle of the rectangular waveform is controlled at software level and it allows readily introduction of the DC component for BAD experiments. 

Fault tolerance techniques aiming to detect transient effects can be mainly divided in three broad categories (1) software-based techniques, (2) hardware-based techniques and (3) l brid techniques. Fault tolerance techniques can be applied at different levels of implementation, starting from the software level down to the architecture description level, the logical and transistor level, until the layout level. In this book, we will focus on hybrid techniques applied at software level. 

It is predictive and target setting (i.e. it determines the system s safety objectives without any architectural limitations). It should be used to identify design precautions necessary to ensure independence, to determine the required software level and to avoid common mode and cascade failures (see Chapters 6-8). 

At software level we can consider the following failnre modes ... 

Partitioning is a technique for providing isolation between functionally independent software components to contain and/ or isolate faults and potentially reduce the effort of the software verification process. If protection by partitioning is provided, the software level for each partitioned component may be determined using the most severe failure condition category associated with that component [ABDOIOO.1.3 Issue E para 2.1.5]. 

There are irmumerous means to reduce the risk of losing an AUV One could increase the vehicle reliability through redimdancy of critical components, use of safety barriers, at the hardware level. At the software level, software fault tolerance techniques, software diversity and formal checking are also techniques that can reduce the risk of system failure. At the operational level, a guided maintenance program is an effective way to reduce the risk. 

The EEA does not go further in subdividing the modeled systems into hardware-and software-only systems. Therefore the EE architect is not directly involved in the system development on hardware or software level. Nonetheless, advising during further development phases is possible. 

Test cases at system and software level are designed by testers with thorough domain knowledge on the basis of the specifications written in natural language, enhanced with semi-formal specification elements. Examples of failures are ... 

It defines five software levels, ranging from Level A (software whose anomalous behaviour would cause or contribute to a catastrophic failure condition for the aircraft) to Level E (software that has no effect on safety). 

The referenee to Level A in the note eould be read to suggest that the number of test eases required to verify a requirement depends on the software level. This was not die intent of die original DO-178B authors. The note was meant to say that if the requirement test eases that have been developed are suffieient to aehieve MC/DC eoverage of the souree eode (whieh is only required at Level A), then enough testing has been done. It would not make any sense to elaim that two test eases would be suffieient at Level B or that no test eases would be neeessary at Level D. 

DO-278A is a variant of DO-178C aimed at CNS/ATM systems. These are groimd-based, rather than airborne, systems. These systems typieally make much more use of commercial off the shelf software (COTS), especially operating systems and databases, than do airborne systems. DO-278A defines six software levels (ALl to AL6), as compared to five in DO-178C (Level A to Level E). 

The tool qualification supplement defines objectives, activities and qualifieation data analogous to the objectives, activities and hfecycle data defined in DO-178C. Just as the objectives are modulated by software level in DO-178C, so the objectives are modulated by TQL in the tool qualification supplement. 

After hazard identification, design constraints are placed and seen from the perspective of human operation, software, etc. especially for programmable electronics (PE). However, this may not completely get rid of hazards, so they are also traced at a software level. For any product safety and reliability are important issue and their intimate relationship has been explained in Fig. 111/1.9.1-1. This is standard practice in product development. 

The functional safety requirements are refined to technical safety requirements and HW and SW safety requirements respectively, on the application level, as well as on all underlying software levels, e.g., the AUTOSAR basic software platform. To verily the top-level safety requirements, safety goals, we therefore need to verify that the AUTOSAR platform implementation in its context can meet the strict requirements of ISO 26262. This is in practice a challenge. There is evidence that production ready... 

ISO 26262-6 2011 Road vehicles - Functional safety - Part 6 Product development at the software level... 

DO-178C defines the work to be completed for a given software level while DO-254 defines the work requirement by data to be produced and submitted for review. 

Software Level Goals G.l Control the speed of the vehicle. 

Each hazardous cause will be translated into software-level safety constraints... 

Figuring out how to record on your computer is not always easy. The combination of hardware, drivers, and software level interface makes troubleshooting a less than intuitive task. And while it is fairly straightforward to isolate output problems, since you can hear whether your card is working or not, input and recording problems cannot always be fixed by ear. To simplify this procedure and avoid crashes, it is best to close other applications while working through this process.

Black Box where the integrity is designed in at the applications software level because the white box claim cannot be made. 

Verification and Validation independent verification at system, hardware and software level is carried out through the entire design process at each development phase to guarantee the consistency with the requirements stated at the previous phase. 

Moreover, there are other possible adaptations to the initial software architecture than the ones described in the range checker example. Simple mechanisms only require adding a new executable entity to a pre-existing software component. However, for more intrusive safety mechanisms, e.g., control-flow monitoring, the monitored executable entities or software components are adapted to provide interfaces for the reporting of checkpoints. Furthermore, if no modification to the application software level is allowed, specific configuration or enhancement of basic software modules are required. Such more complex enhancements of the architecture require more contextual information (e.g., the AUTOSAR system configuration). 

ISO ISO/FDIS 26262, Part 6 - product development at the software level (2011)... 

Vulnerabilities can be located at network, hardware and software level. Hardware vulnerabilities are especially a challenge for security engineering if parts of the embedded systems are employed in a potentially not trustworthy environment. In addition, hardware could generally be equipped with additional malicious components [17]. Reconfigurable means a microcontroller is reprogrammable. This could be because one step in the commissioning process has not been executed. With not tamper proof hardware, an attacker could access hardware components and execute direct attacks on the hardware. 

I will then explain more deeply the consequences at the software level, and what are the key areas of interest on Renault s side, and in particular regarding safety and security of the software embedded in the cars. 

Also for basic software or in AutoSar abstraction levels are addressed but in this case we don t mean horizontal abstraction levels but functional (perspectival) abstraction levels (e.g. hardware abstraction or microcontroller abstraction layer (MCAL)). Nevertheless, the interface between application software and microcontroller still play an important role in the definition of the abstraction level. In early revisions of ISO 26262 the hardware software interface (HSl) was implemented in part 5 (Product development at the hardware level) and 6 (Product development at the software level) and only after the CD version of ISO 26262 it moved into part 4 (Product development at the system level). What is special about this is that the microcontroller as a hardware element, similar to the electronics housing, predetermines essential design characteristics for the software. In order for these two components to interact properly, those characteristics and their potential flaws as well as the functions and their potential failure functions need to be considered. This obviously goes for all component interfaces. In the case of HSl we find a lot of relevant interface parameters. This means, that it is not only about the correct functions of the so-called low-level drivers, which provide information on microcontrollers to the software, the operating system, peripheral (DMA, I/O, bus etc.), internal communication, logic unit, memory or function libraries, which are provided by the computer, but also the systematic protection of potential failure or malftmction at this interface. 

Fig. 4.76 Information flow and phases of activities in product development on software level and scope for software safety concept (SSC)...

Table 5—Correct implementation of technical safety requirement at the hardware-software level... 

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